One in 10 allergic to milk, eggs or peanuts
Already known for their higher-than-usual risk of asthma and environmental allergies, young inner-city children appear to suffer disproportionately from food allergies as well, according to results of a study led by scientists at the Johns Hopkins Children's Center.
The federally funded multi-center study, described online Aug. 13 in the Journal of Allergy and Clinical Immunology, found that at least one in 10 children from four large U.S. cities has a food allergy. However, the true number may be even higher, the investigators say, because the study used highly stringent criteria and counted only the three most common food allergies.
"Our findings are a wake-up call, signaling an urgent need to unravel the causes, contributors and mechanisms that drive the high prevalence of food allergies among an already vulnerable group known for its high risk of asthma and environmental allergies," says senior investigator Robert Wood, M.D., director of pediatric allergy and immunology at Johns Hopkins.
Nearly 3 percent of adults and 6 percent of young children in the United States have one or more food allergies, according to the latest estimates from the National Institutes of Health. Moreover, Wood notes, food allergies among children have been on a steady rise over the last 20 years, and experts have long suspected that children in urban areas are no exception. The new study largely affirms that trend but also points to a subgroup of children who may have higher-than-average allergy risk.
For the study, the investigative team followed 516 inner-city children from birth through age 5, living in Baltimore, Boston, New York City and St. Louis. Each year of the study, the investigators measured each child's exposure to household allergens, conducted physical exams, tracked the children's diets and reviewed their health histories.
The team also analyzed blood samples at 1, 2, 3 and 5 years to measure the presence of food-specific immunoglobulin E (IgE) antibodies to milk, eggs and peanuts. IgE antibodies to food proteins are immune chemicals released by the body that herald a food allergy. Based on blood test results, other clinical findings and symptoms, the investigators classified a child as allergic, possibly allergic, sensitive to a particular substance or not sensitive.
Sensitization to a substance, signaled by the presence of IgE antibodies in the blood, renders a person more likely to develop allergic symptoms, but it is not sufficient to diagnose a true food allergy, which is always marked by clinical symptoms. In this study, the investigative team deemed allergic only those children who had both clinical symptoms and elevated IgE antibodies. This stringent criterion likely underestimates the true number of kids with food allergies, Wood adds.
Overall, more than half (55 percent) of children in the study were classified as sensitive to milk, eggs or peanuts. Nearly 10 percent of them met criteria for a full-blown food allergy. The most common allergy was to peanuts (6 percent), followed by eggs (4.3 percent) and milk (2.7 percent).
An additional 17 percent were classified as "possibly allergic," a subgroup that had elevated IgE antibodies but no clear history of allergic reactions to peanuts, eggs or milk. Twenty-nine percent were classified as "sensitive but tolerant," a group that included those with elevated IgE antibodies and a known history of consuming allergenic foods but who were able to tolerate the foods in question without allergic symptoms.
Breastfed children appeared to have a higher risk for developing food allergies. Children living in houses with higher levels of endotoxin, a molecule released by certain types of bacteria, were less likely to have a food allergy. This latter finding, the investigators say, is consistent with the so-called hygiene hypothesis, which suggests that early-life exposure to certain microbes can play a protective role against asthma and allergies.
Children with food allergies were also more likely to suffer from environmental allergies, wheezing and eczema, an allergic skin condition.
Other institutions involved in the research included Boston University School of Medicine, the Washington University School of Medicine in St. Louis, Columbia University Medical Center in New York, and the University of Wisconsin School of Medicine and Public Health.
The study was funded by National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, under grant numbers NO1-AI-25496, NO1-AI-25482, HHSN272200900052C and HHSN272201000052I. Additional support was provided by the National Center for Research Resources under grants, RR00052, M01RR00533, 1UL1RR025771, M01RR00071, 1UL1RR024156, and 5UL1RR024992-02.
Ekaterina Pesheva, email@example.com (410) 502-9433
Helen Jones, firstname.lastname@example.org (410) 502-9422
Related on the Web:
Newborns Exposed to Dirt, Dander and Germs May Have Lower Allergy and Asthma Risk
First Long-Term Study of Food Allergy Treatment: 'Proceed with Caution'
Egg Therapy Benefits Children Allergic to Eggs
Drinking Milk to Ease Milk Allergy?
Ekaterina Pesheva | Eurek Alert!
Mobile phone test can reveal vision problems in time
11.02.2016 | University of Gothenburg
Proteomics and precision medicine
08.02.2016 | University of Iowa Health Care
Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.
The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
12.02.2016 | Event News
09.02.2016 | Event News
02.02.2016 | Event News
12.02.2016 | Physics and Astronomy
12.02.2016 | Life Sciences
12.02.2016 | Medical Engineering